Furnace



B. s. GILLMOR FURNACE Filed Oct. 16, 1939 IN VENTOR ATTO RN EYS Patented Nov. 19, 1940 er trici:

2 Claims.

This invention relatesl to furnaces and' has for an object to provide a furnace adapted yto receive a down draft at the back from the chimney, to

prevent oxygen being taken from the room, and

5 at the same 'time increase the efficiency of coal consumption by promoting practically complete combustion of almost all gases and smoked particles while combustion of the fuel progressively moves forward in the fire box toward the intake end of the smoke pipe located at the front of the furnace.

A further object is to provide a furnace having a casing extending from front to rear above the fire box and housing a smoke pipe disposed concentrically therein and communicating at the rear end with the chimney, the products of combustion impinging against the outside of the casing so that the smoke pipe is protected, and subsequently entering the smoke pipe at the front of the furnace, the casing receiving cold air from the room to be heated twice, first by the products of combustion in the smoke pipe and second by` the heated casing, before the heated air leaves the casing for distribution to the various rooms.

A further object is to provide a furnace of this character which will be formed of a few strong simple and durable parts, which will be inexpensive to manufacture and which will not easily get out of order.

With the above and other objects in view the invention consists of certain novel details of construction and combinations of parts hereinafter fully described and claimed, it being understood that various modifications may be resorted to within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawing forming a part of this specification:

Figure 1 is a longitudinal sectional view of a furnace constructed in accordance with the invention and showing the smoke pipe and down draft pipe connections with the chimney.

Figure 2 is a cross sectional view taken on the line 2-2 of Figure 3.

Figure 3 is a front elevation of the furnace.

Referring now to the drawing in which like characters of reference designate similar parts in the various views, l designates a furnace, and II a chimney. In carrying out the invention a down draft pipe I2 is disposed in the chimney, and is directed forwardly at the bottom as shown at I3 to enter the fire box of the furnace at the back. The incoming air for supporting combustion in the furnace is heated by the waste products of combustion in the chimney to promote quicker ignition of the fuel than is possible when chilled air is used.

A smoke pipe I4 is disposed longitudinally in the furnace above the fire box I5 and communicates at the rear end With the chimney. The front end of the smoke pipe is provided with a clean out door i6 at the front of the furnace. Communication between the fire box and the smoke pipe is effected by a branch pipe Il which enters the smoke pipe near the front end thereof and at the outer end communicates with the interior of the furnace. Thus the products of combustion will travel from front to rear of a furnace through the smoke pipe I4 and heat the smoke pipe before emerging into the chimney.

A casing I8 is disposed longitudinally in the furnace outside vof the smoke pipe and spaced from the latter so that the products of combustion impinge against the casing rather than the smoke pipe and heat the casing. Since the smoke pipe is arranged concentrically in the casing it will be protected by the casing from flame.

A plurality of upwardly inclined cold air pipes I9 project through the wall of the furnace, as best shown in Figure 3, and communicate With the casing. 'Ihese pipes may be arranged in any preferred manner longitudinally of the casing to receive cold air from the room and conduct the same into the casing. A hot air outlet pipe 20 is connected to the casing intermediate the ends thereof and projects from the furnace for distributing hot air to the various rooms.

A draft door 2l is disposed at the front of the fire box. This draft door may be opened when desired but is normally closed to maintain an airtight re box when oxygen to support combustion is to be taken from the chimney. i

A fuel door 22 is disposed in the front of the fire box. It has been found in practice that no grate is necessary in a furnace of this type so that fuel such as wood and coal may be piled on the bottom of the furnace. Also all gases and smoke particles are consumed during travel from rear to front of the furnace and back again to rear of the furnace before escape into the chimney. As illustrated in Figure 1 the oxygen to support combustion will cause combustion to progressively creep forward in the fuel supply as the fuel is reduced at the rear to a minimum of ashes. This promotes a slow burning fire with resultant economy of fuel combustion, while at the same time the cold air entering the casing will be more efficiently heated as will now be explained.

The hot products of combustion envelop the casing from rear to front thereby heating the casing before entering the branch pipe I1 to escape through the smoke pipe I4. The products of combustion while travelling through the smoke pipe to the chimney heat the smoke pipe I4. Consequently cold air entering through the cold air pipes I9 is heated from two directions, or is heated twice, before escaping through the hot air pipe 20, first by the hot air casing I 8 and second by the hot smoke pipe I4.

From the above description it is thought that the construction and operation of the invention will be fully understood without further explanation.

What is claimed is: Y

l. The combination with a furnace, of a down draft pipe adapted to be disposed in a chimney and to enter the furnace at the rear end thereof,

a smoke pipe disposed longitudinally in the fur` nace and communicating with the fire box of the furnace at the front end of the furnace, said smoke pipe being adapted to enter the chimney, a Acasing surrounding the smoke pipe and space therefrom and adapted to be exposed to the fiame of the re box and protect the smoke pipe, a cold air pipe entering the casing and projecting from the furnace to supply atmospheric air to the casing, and a hot air pipe communicating with the casing for distributing hot air from theA .from the casing, a smoke pipe adaptedto be connected to the chimney and disposed concentrically in the casing and spaced therefrom, and means for establishing communication between the fire box of the furnace and the front end of the smoke pipe, air in the casing being heated by contact with the casing and by contact with the smoke pipe before escaping from the casing.

BOWEN S. GILLMOR. 

